I don't schedule backups, my PIM data is on the Exchange server so I only backup before I install a new application.

I backup to my SD card, my last backup archive was 40+ MB, it would have not fit in the free space left on my device.

Sprite creates a unique file every time it backs up and names it for the day it was created. You are only limited by your space on your SD card. I see no need to backup on a daily basis. I backup about once every two weeks or before I make changes to my system (e.g., reg hacks, loading new software, etc.).

late,
Coz